<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
	</head>
	<body>
		
		<script>
			/* 
			 
			 {
				 
			 }  也表示一个作用域
			 
			 */
	       {
			   let nums = 1;
		   }
			console.log(nums)
		</script>
	</body>
</html>
